Can you upgrade steam bronze to silver/gold later?

[arcy]

Like, not if you have an ATI voucher... but rather, if I purchase HL2:Bronze via steam, and in a month when DOD:Source comes out, I decide I really want that, can I pay the different and "upgrade" to silver?

 

[Ames]

Yes...you can...

 

[eLGee]

Yes. Yes, you can. Yes, you can, but not yet. It'll be possible soon.

 

[kiwii]

yupp, its not avalible yet though,